Utilities need to have enough power plants to meet peak demand at the time it is called for, or they risk causing a blackout. All utilities have a mix of electricity sources, including coal, natural gas, and nuclear power. They decide which power plants to run based on a number of factors, including cost, environmental regulations, and location.

Your electricity bill charges you for your energy use, but how much power does your house need? And how can you reduce your power demand? This post focuses in on the concepts of peak loads, load-shifting, and power planning.

Definitions like “energy is the capacity for doing work” and “power is the rate of doing work or the rate of using energy” don’t do much to differentiate between a kilowatt and a kilowatt hour. This post walks through an example to show why to consider investing in energy efficiency upgrades before installing a solar PV system.